I have a adhd kid in Rachel Carson with IEP. Right now the principal and staff are good to me. Rachel carson is a small school with many kids, and my adhd kid is fine with big crowds and noises. Some kids may find it overwhelming. Since your kid is still in preschool, and I don't know what your child needs for supports, so it is difficult to tell.
My kid has IEP since before preschool because of not only adhd diagnosis. For his adhd diagnosis, he is more hyperactive type than inattentive type. Current principal has been attending IEP team meeting and really involved in school activities. The communication with homeroom teacher seem to be good. I don't bug IEP team that much, and I know that they are overloaded. My kid does not need much support at school even though he has IEP, so so far so good.